Preparation and characterization of ZnO nanospindles and ZnO@ZnS core–shell microspindles

ZnO nanospindles were synthesized by PVP-assisted hydrothermal growth and ZnO@ZnS core–shell microspindles were successfully fabricated by sulfidation of ZnO nanospindles via a facile chemical synthesis. The as-obtained samples were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy and fluorescence spectrophotometer. The results showed that the pure ZnO nanospindles were hexagonal wurtzite crystal structure and the ZnS nanoparticles were sphalerite structure with the size of about 40 nm grown on the surface of the ZnO nanospindles. The measurement of luminescence revealed that ZnO@ZnS core–shell microspindles integrated the luminescent effect of ZnO and ZnS. The broad blue emission of ZnO@ZnS core–shell microspindles were dramatically enhanced, while the orange emission disappeared. In addition, a possible formation mechanism of ZnO@ZnS core–shell microspindles was also suggested based on the results of the experiments.